Anhydrous sodium sulfite

This product is white crystal or powder; odorless.This product is easily soluble in water, very slightly soluble in ethanol, and almost insoluble in ether.Soluble in water (12.54g/100ml water at 0°C; 28.3g/100ml water at 80°C), the solubility is high at 33.4°C, about 28%, the aqueous solution is alkaline, and the pH value is about 9~9.5.Slightly soluble in alcohol, insoluble in liquid chlorine and ammonia.It is easily oxidized to sodium sulfate in the air, and decomposed into sodium sulfide when it is exposed to high temperature.In order to strengthen the reducing agent, it reacts with sulfur dioxide to generate sodium bisulfite, and reacts with strong acid to generate corresponding salts.

Basic information

Quality Index

HG/T 2967—2000

Application

Used as a catalyst for the addition stage reaction in the synthesis of urea-formaldehyde resins.As a reducing agent it protects oxygen-sensitive materials.Also used as antioxidant, antioxidant, neutralizer.

Identify

(1) The aqueous solution (1→10) of this product is alkaline, and the solution shows the identification reaction of sulfite.

(2) The aqueous solution of this product shows the identification reaction of sodium salt.

Check: solution clarity and color

Take 1.0g of this product, add 20ml of water to dissolve, the solution should be clear and colorless.Take 1.0g of this product for thiosulfate, add 15ml of water to dissolve, add 5ml of dilute hydrochloric acid, shake well, and let stand for 5 minutes without turbidity.

Iron salt

Take 1.0g of this product, add 2ml of hydrochloric acid, evaporate to dryness on a water bath, add an appropriate amount of water to dissolve, and check according to the law. Compared with the control solution made of 2.0ml of standard iron solution, it should not be deeper (0.002%).

Heavy metal

Take 1.0g of this product and check according to law.The heavy metal content shall not exceed 20 parts per million.Take 0.5g of this product as arsenic salt, add 10ml of water to dissolve, add 1ml of sulfuric acid, steam it on a sand bath until white smoke emerges, let it cool, add 21ml of water and 5ml of hydrochloric acid, check according to the law, and it should meet the regulations (0.0004%).

Determination of content: take about 0.20g of this product, accurately weigh it, add 50ml of iodine titration solution (0.05mol/L), seal it tightly, shake it to dissolve, and place it in a dark place for 5 minutes.Titrate with sodium thiosulfate titration solution (0.1mol/L), add 1ml of starch indicator solution when approaching the end point, continue to titrate until the blue color disappears, and correct the titration result with a blank test.Each 1ml of iodine titration solution (0.05mol/L) is equivalent to 6.302mg of sodium sulfite.

Chemical use

1. Anhydrous sodium sulfite for film development

2. Used as reducing agent and sulfonating agent in chemical industry;

3. Dechlorinating agents and bleaching agents in the printing and dyeing industry;

4. Stabilizers for chemical fibers, etc.

Storage and transportation attention

Store in a cool, dry and ventilated warehouse.Keep away from tinder heat sources.The packaging is required to be sealed and not in contact with the air.Do not store and transport together with oxidants, strong acids and harmful substances.This product is deliquescent and should not be stored for a long time.Protect from rain and sunlight when transporting.